The present invention relates to storage batteries, especially lead storage batteries, with a plastic monobloc container having vertical walls with separating ribs.
Monobloc containers for lead storage batteries are conventionally produced in several sizes (classes), defining a variety of available battery types. For any given battery type, the capacity of the battery can be varied responsive to need. The need to accommodate different battery types requires the use of different injection molds (for each battery type). Due to cost considerations, this has led to a situation where only a few types (sizes) of batteries are offered. The result has been that only a few standardized outside dimensions are available, with widely differing capacities for any given container type. This is achieved by varying the number of positive and negative plates (i.e., plate groups) within each compartment of the container. This leads to corresponding variations in the cell space which is left free by the installed plate groups. These free spaces are conventionally filled with filler pieces referred to as plug-in separators.
Another expedient for reducing the free spaces in battery containers, to establish the volume required for the plate system to be installed, is to provide the intermediate and end walls with vertical ribs. The vertical ribs serve as spacers, and at the same time stiffen the intermediate walls (i.e., the partitions) while ensuring better electrolyte circulation around the outermost electrode plates of the installed plate groups. An example of such a construction is disclosed, for example, by EP-OS 169,179.
It is also known (for example, from DE-OS 3,117,917 or DE-OS 3,128,224) that the stiffening ribs arranged on the end walls and partitions of the container can be replaced with elastic, spring-like ribs. These ribs are directly formed on the container, extending toward the opposing wall at an angle which deviates from 90.degree.. The use of such ribs is advantageous in that they permit automatic installation of the plate groups, and can be molded to the plate system which is employed. However, a shortcoming is that such ribs can cause damage to the outermost electrode plates during vibrational stresses of the storage battery. This can be remedied by packing spacers against the ribs so that the outermost plates of the plate groups are covered. However, the use of spacers tends to complicate the installation process (with additional components), and makes automation more costly.